The present invention concerns a method for producing a bioactive surface in the form of an active ingredient coating on the balloon of a balloon catheter. The invention concerns also a balloon of the balloon catheter and a balloon catheter.
The so-called “minimally invasive methods” gain increasingly in significance in medicine. In the context of radiology, interventional radiology is to be mentioned in this connection that has contributed significantly to the development of minimally invasive techniques and the devices and prostheses of suitable material required for this purpose. For example, today balloon catheters are inserted by cardiologists as well as radiologists in vessels in order to open them. These procedures may cause a thickening of the vessel wall with consecutive lumen constriction in the area of the expansion by cell proliferation.
By medication release from the surface of the balloon of the balloon catheter, this problem can be counteracted. Typically, an active ingredient that is dissolved in a solvent is applied to the surface of the balloon of the balloon catheter, wherein the solvent subsequently evaporates. The active ingredient is then located on the surface.
Possibilities for obtaining in comparison thereto an improved adhesion of the active ingredient on the surface are disclosed in the documents U.S. Pat. No. 5,102,402 and U.S. Pat. No. 6,129,705. The document U.S. Pat. No. 5,102,402 discloses a balloon catheter coated with medicaments. In this connection, in a first variant microcapsules filled with an active ingredient or medicament are enclosed by folds in the balloon surface and in this way mechanically held in their respective position. In a second variant the microcapsules are glued by means of a bonding agent to the balloon surface.
In the document U.S. Pat. No. 6,129,705 a balloon catheter is disclosed whose surface has a coating in which microcapsules that are filled with an active ingredient are completely embedded. However, filling the active ingredient in microcapsules and the subsequent attachment or embedding of the microcapsules on the balloon surface are comparatively complex and thus expensive methods.
In principle, it is desirable when the surface of the balloon of the balloon catheter has a homogenous and reproducible medicament loading and at the same time is distinguished by a uniform medicament release in the surrounding tissue in the body.
It is therefore a first object of the present invention to provide an advantageous method for producing a bioactive surface on the balloon of a balloon catheter. It is a second object of the invention to provide an advantageous balloon of a balloon catheter. A third object resides in that an advantageous balloon catheter is to be provided.